1. Field of the Invention
The present invention relates generally to an input control device for a personal computer. Still more particularly, the present invention relates to an overlay device with tactile feedback for a touchpad.
2. Background of the Invention
The complexity of functions preformed by personal computers has created a need for more sophisticated input and output devices for controlling the operation of the computer. For example, the mouse was developed to facilitate control of the movement of a cursor on the computer screen. Other input devices for controlling the computer such as a track ball and joystick are widely available.
Keyboards used with desktop computers typically have 100 or more keys. Many of such keyboards include a 10 digit keypad to enable an operator to quickly and efficiently input numbers into a database, for example. Arrow keys, and other special purpose keys, are also included on such keyboards
The keyboards provided in laptop or portable computers, however, necessarily must be smaller than keyboards provided in desktop computers. Accordingly, keyboards used with laptop computers include fewer keys than keyboards in desktop computers. A laptop keyboard typically includes only 85 keys. Most laptop computer keyboards do not include a separate 10-digit keypad as do keyboards in desktop computers. Instead, the functions performed by the 10-digit keypads of desktop computers are added to existing keys on a laptop computer's keyboard. Thus, many keys on a laptop computers keyboard perform two or more functions, each function individually selected by pressing that key in combination with another key.
In a standard 10-digit keypad the keys are aligned vertically and horizontally allowing an operator to quickly press the keys without having to look down. Because the keys on which the numeric function keys are added in the laptop computer are staggered as shown in FIG. 1, the configuration of the numeric keys in a laptop computer's keyboard is different than the configuration in a standard desktop keyboard. This configuration difference is not desirable for operators that must quickly and repeatedly enter numbers into a database. All else being equal, laptop computer operators would prefer to have a full size keyboard, such as the keyboards used in desktop computers.
The sophistication of software, and particularly computer games, has fueled a need for more sophisticated input control devices. Joysticks, game controllers, and other control devices have been developed and are available to satisfy many different software needs. These devices typically plug into a connector on the rear portion of computer chassis. As the computer operator switches between software programs, the operator may have to switch input control devices disconnecting one control device and plugging in another. Often, the computer must be reset ("rebooted") to communicate properly with a newly connected control device.
The lack of room in a typical laptop computer's carrying case and the weight of multiple input control devices makes using multiple input control devices with a laptop computer system less than desirable. Even with a desktop computer system, having multiple input control devices can be cumbersome, as well as substantially increasing the cost of the system. Further, software developers usually are limited to the control devices currently available for computers. Although currently available control devices may not provide the most optimal control scheme for a particular program, computer programs, nevertheless, usually are designed to be operated with one of the available control devices to avoid requiring the operator to incur the substantial expense in buying a new control device that may be useless for other programs.
In sum, there is a substantial need to provide a greater number of input control devices to a personal computer system, particularly to a laptop computer. It would be especially advantageous to have a computer system with increased input control capability without increasing the size, weight, and number of peripheral computer control devices.